I’m a carpenter from Ireland. Building with timber is not common here, but I just completed a medium sized workshop built from reclaimed railway sleepers, lying horizontally.
I installed a backer rod between the timbers, and am now ready for chinking. Sadly, caulking/chinking products are not readily available here. The only sealant type products which adhere to this old, treated timber are very expensive.
I’m wondering if a sand/cement/lime mixture might be best? I could easily poin